Browsing by Author "Tshuma, N."

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    Enhancing food security through microirrigation: Evaluating the contribution of treadle pumps to household food security in Umzingwane district of Zimbabwe
    (2014) Dube, T.; Maphosa, M.; Dube, Z. L.; Ncube, G.; Tshuma, N.
    Amongst a plethora of challenges facing the African continent today is the food security issue. Close to 240 million people in sub-Saharan Africa are food insecure (Bremner, 2012). A number of reasons have been advanced to explain the food insecurity situation of which inter-alia include climate change, low food and agricultural productivity and production. This article is centred on assessing the use of treadle pumps micro irrigation technologies strategy in an attempt to counter low food and agricultural productivity in Umzingwane district of Zimbabwe. Both qualitative and quantitative approaches were used with data being collected through questionnaires, focus group discussions and key informant interviews. A total of 100 smallholder farmers participated in the study which covered 6 Wards. Study findings reveal that the use of treadle pumps improves household food security though this inevitably comes at a cost to the natural environment. This is largely due to the way in which this form of micro-irrigation is practiced in the District. However, notwithstanding the positive contribution of treadle pumps to household food security, the use of these pumps is fraught with a number of challenges some of which include lack of backup services, spares, marketing and an unsupportive institutional environment
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    Synthesis of glass-based catalysts for biodiesel production from a blend of beef tallow and waste cooking oil
    (ELSEVIER, 2025-01-16) Mashamba, M.; Tshuma, L.; Moyo, L. B.; Tshuma, N.; Simate, G. S.
    The perennial disparity between supply and demand of energy as a result of burgeoning populations, expeditious urbanisation and industrialisation has driven the need for alternative energy sources. Biodiesel has emerged as a promising vehicular fuel due to its similar physiochemical properties to mineral diesel and its potential to minimise environmental impact. However, the commercialisation of biodiesel production faces challenges, particularly related to feedstock and catalyst selection. This study explored the utilisation of waste laboratory glass to synthesize heterogeneous catalyst for producing biodiesel from a blend of beef tallow and waste cooking oil. Heterogeneous catalysts are crucial for achieving high conversion efficiency, reusability, ease of separation and minimal environmental degradation. The particle size distribution of the catalysts was heterogeneous, with 23.33 % of particles passing 710 μm, 30.83 % passing 500 μm, and 45.83 % passing 350 μm. XRF analysis revealed that silica was the primary elemental constituent, comprising over 70 % of the total sample composition, and successful incorporation of Na, Mg, and Zn in the respective treated catalysts was observed. FTIR analysis of the calcined and uncalcined catalysts showed a sharp decrease in hydroxyl functional groups, indicating successful calcination. All glass-based catalyst samples exhibited strong Si-O-Si vibration stretches around 1100cm− 1, confirming the presence of silicon as the glass precursor. The FTIR results of the crude biodiesel samples produced by the catalysts at 15 min intervals showed that the NaOH treated glass-based catalyst exhibited the fastest transesterification reaction.. The results showed that the NaOH treated, MgO treated, Zncl2 treated, and control glass-based catalysts achieved catalyst yields of 80.63 %, 86.13 %, 91.38 %, and 94.25 % respectively, upon calcination. Furthermore, the produced biodiesel was characterised to evaluate its fuel properties: the tested parameters kinematic viscosity, density, flash point and acid value were within the desirable limits for biodiesel according to American and European standards . Moreover, the catalyst showed that it can be reused as after six cycles of reuse a biodiesel yield above 89 % was realised.